The present invention relates to a character reader. More particularly, the invention relates to a character reader which provides high speed readout processing for characters on a sheet by high speed positioning of a readout head to a character domain on the sheet indicated by line marks.
The present invention is not limited to a character reader of the aforedescribed type. The character reader of the invention is capable, however, of distinctive use as a page reader, for example, which reads out characters recorded in several lines on the sheet by scanning with a sequentially switched readout head.
In general, the line marks are recorded on a sheet of a page reader for indicating the character domains. The readout head is positioned in the character domain by positioning said head at the line marks. In this case, a rough position information of the line on the sheet to be read out is supplied to the page reader, that is, to a character reader from control equipment. The readout head is thereby positioned. The readout head is then finely positioned or adjusted according to the information regarding the line marks detected by the head so that said line marks and said readout head are aligned with each other at their centers. Thus, characters on the desired line may be read out.
The aforedescribed method for reading out characters after fine adjustment of the readout head with respect to the line mark has the advantage of eliminating a control command for such accurate positioning of the readout head from the control equipment. Any suitable readout head such as, for example a flying spot scanner or diode array, may be utilized. If a flying spot scanner is utilized, the scanning line is determined by controlling the bias current. If a diode array scanner is utilized, the scanning line is determined by shifting the array in parallel. Hereinafter, operation of the character reader of the invention is explained using an example with a photodiode array scanner.
An object of the invention is to provide a character reader which overcomes the disadvantages of character readers of known type.
Another object of the invention is to provide a character reader of simple structure, which provides accurate readout at high speed.
Still another object of the invention is to provide a character reader of simple and uncomplicated structure, which is inexpensive in manufacture.
Yet another object of the invention is to provide a character reader of simple structure, which is inexpensive in manufacture, and functions efficiently, effectively, reliably and at high speed to provide accurate character readout.